A study recently published in the Journal of the American Medical Association found that about one-third of U.S. emergency departments closed during a 20-year period ending in 2009.

According to UC-San Francisco researchers who conducted the study, the ED closures predominately affected safety-net hospitals that see a large proportion of low-income patients.

In a California Healthline Special Report by Kelly Wilkinson, experts discussed some of the factors that likely contributed to the recent decline in EDs.